After all this torturous info, I still believe that taking light catamaran is a way to go

Actually rivers part wasn't all that bad. I was moving, I slept full nights (I couldn't do much at night with inflatable hulls around snags) and I was worm and dry finally and I had plenty of fresh water
Sailing Atlantic side was much more exhausting in the weather we had.

Spindennis.
I think you are on a right track. Don't expect to be fast. But we have had many instances when slow but steady won.

I personally don't see any advantages in bi-sail rig and I see quite a few disadvantages - it seems like windward sail always will be in a way of a person on a board, and leeward sail is hard to control. But idea is around for so long so it may have some merits.

I saw on another forum that you are getting your towing set-up right. Just think light. Try to make your boat as light as possible.

Good luck
Vlad